Angle-measuring devices of this type are used to measure rotary motions of a shaft over one or more rotations. The rotary motion is determined either incrementally or absolutely. The output measured value as a function thereof, is a sequence of counting pulses, a counter value or a code word. Angle-measuring devices are used particularly for machine tools or machining centers for measuring rotary motions. The determination of angles of rotation exactly to only a few angular seconds is crucially important, for example, for rotary tables or swivel heads of machine tools, C-axes of turning machines, but also in the case of printing mechanisms of printing machines. Since exceedingly precise measuring results are attainable when using optical measuring principles, angle-measuring devices of this kind are frequently equipped with an optical measuring system. In this context, usually transparent graduation disks are used, on which an angle graduation or angle scaling is applied. In the interest of a precise measuring result, the graduation disks must be secured exactly on the component to be measured.
German Published Patent Application No. 102 15 997 describes a rotary encoder that has a self-centering clamping device, and in which a shaft is accommodated so as to be enclosed by an encoder shaft as carrier element for a graduation disk.